The invention relates generally to gas-liquid separators, and more particularly, to a gas-liquid separator for an alkaline electrolyzer.
Various types of hydrogen production systems have been designed and are in use. For example, electrolyzer systems generate hydrogen through electrolysis of water. The hydrogen acts as an energy carrier, and can be converted back to electricity for power generation or distributed for use as a fuel. Typically, hydrogen generated from such systems is purified and compressed for storage before it is consumed in an end use system. For example, the end use system may be of a business or industrial nature where the stored hydrogen is used for power generation through hydrogen-powered internal combustion engines, fuel cells, and turbines. Moreover, the stored hydrogen may be distributed to a consumer for powering a vehicle or for use in certain residential applications such as cooking, and so forth.
In certain systems, an alkaline electrolyzer is used for hydrogen generation. Typically, an alkaline electrolyzer uses a liquid alkaline electrolyte such as aqueous potassium hydroxide or sodium hydroxide to facilitate electrolysis of water for generation of hydrogen and oxygen. Further, hydrogen and oxygen are produced in cathodic and anodic compartments respectively of the alkaline electrolyzer. In addition, hydrogen-electrolyte mixture and oxygen-electrolyte mixture from the cathodic and anodic compartments are directed to individual gas-liquid separators for separating the hydrogen and oxygen from the electrolyte.
In operation, the rate of production of hydrogen in the cathodic compartment is different than that of oxygen in the anodic compartment, thereby resulting in variations of the electrolyte level in the individual gas-liquid separators. It is desirable to monitor and control the electrolyte level in the gas-liquid separators to avoid a situation where gas is drawn into the electrolyzer, producing an explosive hydrogen-oxygen mixture. In certain systems, the electrolyte level is monitored using sensors in the gas-liquid separators. Further, the electrolyte level may be controlled via tubes and appropriate valving to achieve the desired electrolyte level in each of the gas-liquid separators. Incorporation of functionalities to monitor and control the electrolyte level is a challenge due to costs and functionality issues. Moreover, a temperature gradient between the two separators may also result due to the varying level of the electrolyte in the respective gas-liquid separators. As a result, the thermal management of the gas-liquid separators may be a challenge in such systems.
Accordingly, there is a need for a gas-liquid separator that provides the separation of gas and liquid in a system by employing a relatively simple and cost effective technique. It would also be advantageous to provide a gas-liquid separator for an alkaline electrolyzer that will separate the hydrogen and oxygen generated in the electrolyzer from the electrolyte, while preventing the formation of explosive hydrogen-oxygen mixture.